Humidity Control Calculator

Calculate humidifier or dehumidifier capacity needed to reach target relative humidity in your grow room.

Room Volume

cu ft

Current Relative Humidity

Target Relative Humidity

Room Temperature

°F

Tab to move between fields

Moisture Removal/Addition

1.1 pints/day

Device Needed

Dehumidifier

Est. Run Time0.9 hrs/day

Est. Monthly Cost$1.76

How to Use This Calculator

Enter your grow room volume in cubic feet (Length × Width × Height) and measure the current relative humidity (%).
Enter your target relative humidity — vegetative stage typically 60–70%, flowering stage 40–50%.
Enter the room temperature in °F — warmer air holds more moisture, affecting device sizing.
Review the Moisture Removal/Addition (pints/day) and Device Needed (humidifier or dehumidifier) outputs.
Use Est. Run Time (hrs/day) and Monthly Cost to size and budget the humidity control equipment.

How the result changes with Current Relative Humidity

Room Volume: Cubic footage of your grow space (L × W × H).
Current Relative Humidity: Measured humidity in the room right now.
Target Relative Humidity: Desired humidity level (veg: 60-70%, flower: 40-50%).
Room Temperature: Warmer air holds more moisture, affecting device sizing.

Identify Input Parameters
4 parameters
Room Volume = 96, Current Relative Humidity = 65, Target Relative Humidity = 50, Room Temperature = 75 = 4 input(s) provided
Calculate Moisture Removal/Addition
Moisture Removal/Addition
1.1 = 1.1
Calculate Device Needed
Device Needed
Dehumidifier = Dehumidifier
Calculate Est. Run Time
Est. Run Time
0.9 = 0.9